While I certainly enjoy exchanging email with my LHC colleagues (in limited quantities, of course), I don’t get to see many people from the LHC community in person on a regular basis. We’re just a little group of particle physicists here in Lincoln, NE. To see more colleagues face to face, I typically have to take a trip to CERN (I go maybe two or three times a year) or to Fermilab, a big hub for US CMS activity (I go there more often than to CERN).
So, it was a great pleasure to get to see two of my fellow US LHC bloggers within one week, and I didn’t have to go to either Fermilab or CERN! First, I was able to convince my old friend Michael to come to UNL to give a colloquium about electroweak physics at the LHC. Michael is currently co-leader of CMS’s electroweak physics group, and has worked on that slice of particle physics for a long time. I enjoyed the talk (of course); it gave me some perspective on where we are in electroweak physics in general, and where it is at the LHC. The W and Z bosons, the key particles of the electroweak theory, were discovered in the 1980′s — a long time ago, already — and have been characterized in great detail. Just saying that we have observed them at the LHC isn’t really interesting in these times. What is interesting is how we are putting the W and Z to use as probes of other particles. Just as we have long used particles such as electrons and neutrinos to understand the structure of the proton (by scattering them off protons), we are now using the production properties of W’s and Z’s to understand the contents of the protons that were used to create them. Or, as one of my colleagues asked during question time at the end, “Why wasn’t the title of this talk ‘QCD at the LHC’?” I can always count on MIchael to teach me something new.
And then, just one week later, I was at the annual US CMS collaboration meeting, hosted by our colleagues at Notre Dame. I had never been to Notre Dame before, and was impressed by their facilities. I’d have to say that these meetings are a bit more about “business” than “physics”, in that we’re not talking about specific measurements as much as the broader picture of where we are and where we are going with the LHC, and how the US component of the CMS collaboration can best take advantage of our strengths for the benefit of the entire experiment. In the year since the last US CMS meeting, everything has changed — last May, we were just beginning to record collision data, and now we have something like a thousand times more data than we did then (with perhaps another factor of ten to come this year, if we’re lucky.) That gives us a lot to be happy about, but of course we can also see where the challenges are. As collision rates increase, it will be a struggle to keep our trigger rates down to something manageable. Processing all of the data we record will be a strain, in part because of the sheer volume of data, but also because of the increased complexity of individual events. Already we need to start thinking about how we will upgrade the detector to handle collision rates that are anticipated to be a factor of ten to a hundred higher within a few years.
This meeting is always a good chance to catch up with US friends whom I haven’t seen for a while. It’s been ages since I’ve seen fellow US LHC blogger Robin, for instance. Of course the meeting was so busy that I barely had a chance to say hello. But ha, I managed to blog about the meeting before her!
And if all of this wasn’t enough — in between these two events, we also had an event for the Nebraska HEP group. We made the US CMS meeting an excuse to bring just about every member of our group home to Lincoln for a visit. It is extremely rare for all of us to get together, but it is almost always a valuable experience. We spent two and a half days going through everything that’s happening in our group (it’s a lot!), trying to figure out how we can work together more creatively, and just hanging out a bit. I really enjoyed seeing everyone.
I’m looking forward to seeing all of these people again soon…but I’m probably going to have to travel further afield to do so.